Development of photographic silver halide material

ABSTRACT

A PROCESS IS DESCRIBED FOR DEVELOPING AN EXPOSED PHOTOGRAPHIC SILVER HALIDE ELEMENT WHEREIN THE DEVELOPMENT IS CARRIED OUT IN THE PRESENCE OF A WATER-SOLUBLE POLYMERIC COMPOUND OBTAINED BY POLYADDITION OF A DIHYDRIC ALCOHOL OF THE FORMULA HO-X-OH, X BEING ARYLENE, A STRAIGHTCHAIN OR BRANCHED-CHAIN C2-C8 ALKYLENE, C2-C8 ALKENYLENE OR C2-C8 ALKYNYLENE GROUP, CYCLOALKYLENE OR ALKYLENE-CYCLO-ALKYLENE, WITH A BISEPOXIDE OF THE FORMULA:   ((-O-CH2-)&gt;CH-CH2-O)2-Z   Z BEING A STRAIGHT-CHAIN OR BRANCHED-CHAIN C2-C8 ALKYLENE GROUP. THE SPEED AND DEVELOPABILITY OF THE SILVER HALIDE ELEMENT IS SUBSTANTIALLY INCREASED BY THE PRESENCE OF THIS POLYADDITION COMPOUND. BY INFECTIOUS DEVELOPMENT OF SILVER CHLORIDE AND SILVER CHLOROBROMIDE EMULSIONS IT IS POSSIBLE BY MEANS OF THESE POLYADDITION COMPOUNDS TO OBTAIN VERY CONTRASTY LINE AND SCREEN IMAGES AND SHARPLY DEFINED SCREEN DOTS AND TO REDUCE THE FORMATION OF PEPPERS WHEN USING SOMEWHAT EXHAUSTED DEVELOPING BATHS.

United States Patent US. Cl. 96-663 22 Claims ABSTRACT OF THE DISCLOSURE A pocess is described for developing an exposed photographic silver halide element wherein the development is carried out in the presence of a water-soluble polymeric compound obtained by polyaddition of a dihydric alcohol of the formula HOXOH, X being arylene, a straightchain or branched-chain C2-C3 alkylene, C -C alkenylene or C -C alkynylene group, cvcloalkylene or alkylene-cyclo-alkylene, with a bisepoxide of the formula:

Z being a straight-chain or branched-chain C -C alkylene group. The speed and developability of the silver halide element is substantially increased by the presence of this polyaddition compound. By infectious development of silver chloride and silver chlorobromide emulsions it is possible by means of these polyaddition compounds to obtain very contrasty line and screen images and sharply defined screen dots and to reduce the formation of peppers when using somewhat exhausted developing baths.

This invention relates to a process for producing photographic silver images by development of an exposed lightsensitive silver halide in the presence of compounds influencing the sensitometric characteristics of light-sensitive silver halide emulsions by an increase of the speed and/or the gradation. The present invention further relates to the compounds used in said process, to their preparation and to photographic materials and developing baths containing said compounds.

It is known that the development of continuous tone images by means of the usual developers such as hydroquinone/p-methylaminophenol developer con be accelerated by the use in the photographic material or the developing bath of polyoxyalkylene compounds, preferably those having an average molecular weight above 1500, such as polyethylene glycols, alkylene oxide polymers obtained by polymerising alkylene oxide in the presence of hexitol ring dehydration products, aliphatic alcohols, aliphatic acids, amines, amides and phenols (cfr. US. patent specifications 2,240,472 of Donald R. Swan, issued Apr. 29, 1941, 2,423,549 of Ralph Kingsley Blake, William Alexander Stanton and Ferdinand Schulze, issued July 8, 1947, 2,400,532 of Ralph Kingsley Blake and Walter Deney Baldsiefen, issued May 21, 1946 and 2,716,062 of Burt H. Carroll and Norman P. Beach, issued Aug. 23, 1955, and United Kingdom patent specification 748,745 filed June 28, 1954 by Kodak Co.). By the favourable effect of these compounds on the development, the final sensitivity of the silver halide emulsions is increased.

It is also known e.g. from German patent specification 1,141,531 filed I an. 24, 1962 by Perutz Photowerke G.m.b.H., that polyoxyalkylene compounds when used in 3,746,545 Patented July 17, 1973 combination with so-called lith-developers (infectious development), which are developers comprising a bisulphiteaddition product of an aliphatic aldehyde or ketone such as formaldehyde bisulphite, and hydroquinone as the sole developing substance, restrain the development rate while increasing the gradation. On account of the very contrasty development obtained therewith, polyoxyalkylene compounds were found very suitable for use in the lith-development of silver halide emulsions of the graphic arts type i.e. of the type used for photochemical reproduction of line or screen images, which are generally silver chloride and silver bromochloride emulsions comprising at most 50 mole percent of bromide.

Polyoxyalkylene compounds, however, when used in silver halide emulsion layers, impair the keeping qualities of these layers, particularly at high temperatures and elevated degrees of relative humidities in that they induce a substantial increase of fog. It was also found that when these polyoxyalkylene compounds are incorporated into silver halide emulsions to increase the speed, they very often impair the image tone of the developed silver by forming brown and reddish brown images. Moreover, polyoxyalkylene compounds when used in infectious development greatly increase the formation of peppers.

Peppers are black spots of a very high density which are irregularly produced during the development in the areas of the light-sensitive emulsion which are slightly exposed. These peppers when they are present in a high amount markedly degrade the quality of a screen image reproduction by deforming the screen dots and/or soiling the areas which were practically unexposed. The phenomenon of pepper particularly arises when partly air oxidized or somewhat exhausted developing baths are used.

It has now been found that the developability and sensitivity of photographic silver halide emulsions can be substantially increased on development-the keeping qualities of the said emulsions not being impaired to a noteworthy extent-by carrying out the development in the presence of water-soluble polymeric compounds obtained by a polyaddition reaction of a dihydric alcohol as defined hereinafter with a bisepoxide as defined hereinafter, the hydrogen atoms of the hydroxyl groups in the resulting polyaddition compound being optionally wholly or partly substituted.

It has further been found that the development of line and/or screen images in silver chloride and silver chlorobromide emulsions by means of so-called lithdevelopers as described above, in the presence of the polyaddition compounds of the invention, produces very contrasty silver images, yields very sharply defined screen dots and occurs with the formation of a smaller number of peppers than is the case with known polyoxyalkylene compounds, and furthermore can take place within a broad interval of time without harm to the image quality.

Therefore, in accordance with the present invention there is provided a process of developing photographic materials comprising exposed silver halide, wherein the development is carried out in the presence of a watersoluble polymeric compound obtained by polyaddition of a dihydric alcohol and a bisepoxide as defined hereinafter.

The invention further provides photographic lightsensitive silver halide materials and photographic developing compositions comprising a water-soluble polymeric compound obtained by polyaddition of a dihydric alcohol and a bisepoxide as defined hereinafter.

The water-soluble polymeric compounds of use according to the present invention are obtained by polyaddition of a dihydric alcohol corresponding to the formula:

HO-X-OH wherein with a bisepoxide corresponding to the formula:

wherein Z stands for a straight-chain or branched-chain alkylene group which has from 2 to 8 C-atoms and may contain one or more oxygen bridges, for example, ethylene, tetramethylene, l-methyltrimethylene, and ethyleneoxy-ethylene.

The water-soluble polymeric compounds for use in accordance with the present invention are compounds comprising units of the following structure:

L R. R. I

wherein:

X and Z have the same significance as above, and

R stands for hydrogen, an alkyl group, a substituted alkyl group e.g. a cyanoethyl group, a -CO- R group, -CONHR group or SO R group wherein R stands for a monovalent saturated or unsaturated aliphatic group for example alkyl and alkenyl, a --OO --CH=CH-COOH group or its bisulphite addition product, a -CO-C H -SO H group, an aryl group or a heterocyclic group or such groups carrying one or more substituents.

As noted above, the compounds of use according to the present invention are prepared by reaction of a dihydric alcohol with a bisepoxide as defined above. In general, the starting products are made to react in an equimolar ratio, though an excess of one of them is not harmful since the reaction proceeds very smoothly and generally not in an exothermic way. The following general procedure can be given for the preparation of the polyaddition compounds of use according to the present invention.

To 1 mole of a dihydric alcohol a catalytic amount of sodium methylate is added and then the mixture is preheated to a temperature of approximately C. Then 1 mole of bisepoxide is added portion-wise with stirring whereupon the reaction mixture is heated to a temperature comprised between 100 and 180 C. and kept at this temperature for a certain time (see table-reaction time). The final products formed are much more viscous than the mixture of starting products. Quantitative yields of well Water-soluble products are obtained.

In the following table a survey of suitable starting products and reaction conditions is given. The possible epoxide groups in the final product obtained, which may be due to unreacted bisepoxide or which are terminal epoxide groups in the polyaddition compounds formed, are determined by titration with perchloric acid in acetic acid medium comprising hexadecyl trimethyl ammonium bromide. The residual epoxide groups are given on a percentage basis of the milliequivalents of epoxide groups found relative to the milliequivalents of epoxide groups used on starting the reaction.

Reac- Reac- Residual Polytion tion Intrinepoxide addition temp. time sic visgroups compound Dlhydric alcohol Bisepoxide 0.) (hours) cosity (percent) 0 O 1 HOCHCHOH H2O CH-C r (CH2) 2-0CH2CH-CH: 72 0, 078 5 II H0(CH2) -OH Same as above 120 72 0. 116 6. 5 III HO(CH2)4OH do 72 0.068 8 IV H0 (OHZ)5 0H 100-120 24 8 v HO-(CH2) -OH dn 100-130 62 0.107 2 VI HO-GHz-CH0H do 100-120 100 0.099 4. 5

VII. HOCHz-CH3(lJH-0H do 150-170 40 0.1 6.5

VIIL HO--GH -CH=GH--CH2-0H 2;- do F 45 0.105 5 IX HO-CH --C=C-CHg-OH do 120 60 0.020 3. 6

X OH do e 24 0. 070 4. 5

XI HO--CH1@-CH2OH do r 150 34 0.078 2.5

XII- HO-Q-OH do 130 3 0.112 1 As is illustrated in the preparation below, the hydrogen atoms of the free hydroxyl groups in the polyaddition compounds obtained may be partly or wholly substituted by reaction with compounds which are reactive with respect to an active hydrogen atom of a hydroxyl group for example an acid chloride or acid anhydride such as acetic anhydride, succinic anhydride, maleic anhydride, and ortho-sulphobenzoic anhydride, a sulphonyl chloride, isocyanates or unsaturated alkylating compounds, e.g. a vinyl compound such as acrylonitrile and methacrylonitrile.

PREPARATION To a refluxing solution of 39.6 g. (0.15 mole) of polyaddition compound III in 200 ml. of anhydrous dioxan, a solution of 36.7 g. (0.375 mole) of maleic anhydride in 200 ml. of anhydrous dioxan was dropwise added in minutes. Refluxing was continued with stirring for 8 hours whereupon the solution formed was concentrated by evaporation till dry and the residue was washed three times with anhydrous toluene heated to 70 C. in order to remove the residual maleic anhydride. Each time the toluene solution was decanted and then the residue was dried at 60 C. under vacuum. Yield: 75 g.

The reaction product of the said hydroxyl containing polymer with maleic anhydride may further be allowed to react with a bisulphite thus forming a bisulphite addition product. The bisulphite used is preferably an alkali metal bisulphite.

The compounds used according to the present invention can be present in the developer bath or can be added to the coating composition of a silver halide emulsion layer and/or incorporated into a water-permeable layer which when coated under or on top of the emulsion layer forms a water-permeable system with the silver halide emulsion layer and is then in effective contact with the silver halide.

The compounds of use according to the invention can be incorporated into the coated emulsion layer either by treating the emulsion layer with an aqueous solution of these compounds or by coating this layer with a waterpermeable layer containing the said compounds, or also by bringing the said compounds from a water-permeable layer lying under the emulsion layer and comprising said compounds by diffusioninto effective contact with the silver halide.

The water-soluble compounds of the invention can be added to the light-sensitive silver halide emulsion during different preparation steps of the light-sensitive material; for instance they can be incorporated therein as a separate addition either mixed with one or more ingredients, which are used in the preparation of the silver halide grains during the physical or chemical ripening process, or another moment preceding the application of the emulsion.

The polyaddition compounds of the invention are preferably added to the silver halide emulsion composition after the chemical ripening process and just before coating the emulsion.

The polyaddition compounds are preferably added from a solution in water or in an aqueous mixture of water and water-miscible organic solvents such as ethanol that do not impair the photographic properties of the light-sensitive silver halide emulsion.

The optimum amount of polyaddition compound added to the silver halide emulsion depends on the compound itself on the nature of the colloid binding agent for the silver halide grains, and on the amount and the kind of the silver halide in the emulsion. In general, however, the polyaddition compounds are added to the light-sensitive material in amounts ranging from 10 mg. to 10 g. per mole of silver halide. In the developing bath they are normally used in amounts ranging from 10 mg. to 5 g. per liter. If necessary, these compounds can also be added in amounts exceeding these limits.

The step of influencing the sensitometric characteristics of silver halide emulsions by means of the polyaddition compounds of the invention can be combined with a method known as chemical sensitization, in which together with the above-mentioned polyaddition compounds chemical sensitizers are used, e.g., sulphur-containing compounds such as allyl isothiocyanate, allylthiourea or sodium thiosulphate, reducing compounds such as the tin compounds described in the Belgian patent specifications 493,464 filed Jan. 24, 1950 and 568,687 filed June 18, 1958 both by Gevaert Photo-Producten N.V., the iminoaminomethane sulphinic acid compounds described in the United Kingdom patent specification 789,823 filed Apr. 29, 1955 by Gevaert Photo-Producten N.V., or noble metal compounds such as gold, platinum, palladium, iridium, ruthenium, and rhodium compounds as described by R. Koslowsky, Z. Wiss. Phot. 46, 65-72 (1951).

The polyaddition compounds employed in the present invention can also be used in combination with stabilizers and [fog-inhibiting compounds for the silver halide emulsion, for instance with mercury compounds such as those described in Belgian patent specifications 524,121 filed Nov. 7, 1953 by Kodak Co. and 677,337 filed Mar. 4, 1966 by Gevaert-Agfa N.V. and in published Dutch patent application 6715932 filed Nov. 23, 1967 by Gevaert- Agfa N.V. with organic sulphur-containing compounds that form an insoluble silver salt with silver ions, with heterocyclic nitrogen-containing thioxo compounds such as benzothiazoline 2 thione and 1-phenyl-2-tetrazoline-5- thione, the compounds described in the Belgian patent specifications 571,916 and 571,917 both filed Oct. 10, 1958 by Gevaert Photo-Producten N.V., and tetraor pentaazaindenes especially those substituted by hydroxyl or amino groups. Examples of the latter compounds have been described by Birr, Z. Wiss. Phot. 47, 2-58 (1952), The combination with sensitizing and stabilizing cadmium salts such as cadmium chloride in the light-sensitive material as well as in the developing bath can also be applied.

In addition to the above stabilizing and chemical sensitizing agents other compounds, which sensitize the photographic emulsion by development acceleration, such as organic onium compounds and polyonium compounds, preferably of the ammonium or sulphonium type, e.g. quaternary tetraalkylammonium salts, alkylpyridinium salts, bisalkylene-pyridinium salts, alkylquinolinine salts, trialkylsulphonium salts, onium derivatives of amino-N-oxides as described in United Kingdom patent specification 1,121,- 696 filed Oct. 7, 1965 by Gevaert-Agfa N.V., and iodonium compounds for instance diphenyl iodonium chloride as described in United Kingdom patent specification 1,119; 075 filed Oct. 7, 1965 By Gevaert-Agfa N.V. can be used together with the polyaddition compounds according to the invention in the developing solution as well as in the light-sensitive material. Other ingredients, such as colour couplers, developing substances, hardening agents, plasticizers, and Wetting agents, can also be added to the emulsion in the ordinary way.

The development of low-sensitive as well as of highsensitive, of fine-grain as well as of coarse-grain silver halide emulsions is accelerated by the action of the abovementioned polyaddition compounds. These products can be applied for accelerating the development of X-ray emulsions as well as of a wide range of spectrally or non-spectrally sensitized emulsions. They can be incorporated into the photographic emulsion either with or without spectral sensitizers and can be used for increasing the sensitivity of negative emulsions as well as of positive emulsions. As noted above the polyaddition compounds of the invention are also particularly suitable for the development of silver chloride and silver chlorobromide emulsions comprising at most 50 mole percent of silver bromide for reproducing line and screen-images with hydroquinone formaldehyde bisulphite developers.

The following examples illustrate the present invention.

7 EXAMPLE 1 A conventional ammoniacal high-sensitive gelatino silver bromoiodide (4.2 mole percent of iodide) emulsion ready for coating, which comprised per kg. an amount From the above results it clearly appears that, as compared with the use of polyethylene glycols as development accelerators, which have a high speed-increasing eifect in the fresh materials but not in the stored materials, the compounds of the invention increase the speed both in the of silver halide corresponding to 50 g. of silver nitrate, 625 mg of 5 methy1 7 hydroxy s triazolo[l,s a]py fresh matenals and the stored materials and g1ve substanrimidine as a stabilizer, as well as other emulsion addenda less fog, especlally P' g, than the P such as hardener and coating aid, was divided into several ethylene EW aliquot portions. To each of these portions one of the EXAMPLE 2 compounds listed in the table 'below was added as development accelerator in the amount given. The emulsion Example wasfepeated Wlth the (inference that the portions were then coated on '51 subbed support and dried. Chmpouhds hsted 1n the table below Were added as The materials obtained were then exposed under velopment aeeelelatorsidentical circumstances through a grey wedge and de- The following results were attained.

TABLE Fresh materials Stored materials Speed Speed Mg. per kg. Compound added emulsion Fog Grad. I II Fog Grad. I II 0. 05 0. 54 100 100 0. 00 0. 43 132 01 Polyethylene glycol with average molecular Weight of Polycondensation product of triethylene glycol and CH2--CHCHz-O(CH2)20CH2-CH CH2 prepared in an analogous way as the compounds of the invention 300 0. 0s 0. 55 145 132 0. 12 0. 55 175 200 Do 1,000 0.05 0. 54 155 220 0.35 0. 47 115 53 Compound VII 300 0. 07 0. 57 138 200 0. 03 0. 53 152 174 1, 000 0. 07 0. 50 152 240 0. 10 0. 50 105 145 Compound XIII- 300 0.08 0. 55 125 102 0. 0s 0. 57 138 230 5 1, 000 0.08 0. 51 132 120 0.11 0. 50 120 100 Compound XIV..- 300 0. 05 0. 57 115 159 0. 0s 0. 55 152 150 o. 1, 000 0.05 0. 55 125 13s 0. 07 0. 52 158 13g veloped for 8 min. at C. in a developer of the follow- These results show that the compounds of the invention ing composition: have a higher speed-increasing effect and gives less fog Water Q) 750 in the Stored materials than polyethylene glycols. They p MOnomethy1aminopheno1 Sulphate 2 also show that closely related compounds formed from Sodium sulphite (anhydrous) g 100 P y y gly l dihydric alcohols having recur- Hydroquinone g 5 g e hylene xide units (cfr. US. patent specification Borax, granular g 2 3,158,484 of Jozef Frans Willems, Robrecht Julius Thiers Water to make 1000 ml. and Joseph Louis De Munck, issued Nov. 24, 1964) give The values of the speed, gradation and fog for m higher fog values than the compounds of the invention rials developed immediately after coating (fresh mat and as regards the1r speed mcreasing effect in stored materials) and materials that before development were con- T1315, are more dependent on the concentration e ditioned for 36 hours at 57 C. and 34% relative humidity E MPLE (stored materials) are listed in the table below. The values 3 I and II given for the speed are relative values corresponding to a density 0.1 and 1 respectively above the fog Exampclle g g g dlfference that the value; the value of 100 Was given to the speed values I compoun s m t e ta 6 e 0W were added as and II of the freshly prepared material comprising no Velophlent acceleratofsdevelopment accelerating compound. The followmg results were attamed.

TABLE Fresh materials Stored materials Speed Speed Mg. per kg. Compound added emulsion Fog Grad. I II Fog Grad. I II 1 1 ht 0.10 0. 53 100 100 0.13 0. 55 80 l l 1 lb a e emoecuarwei ia ih fi yco nav mg g 0.18 0.55 159 200 0. 54 0. 43 so 15 D0 300 0.27 0. 59 159 240 1.10 2s Compound I. 100 0. 12 0. 69 120 173 0. 12 0. 65 126 144 300 0. 17 0.71 115 155 0. 10 0.70 132 200 Do 1,000 0.15 0. 50 125 155 0. 10 0.52 132 144 Com ound 11- 100 0.14 0. 70 115 0.15 0. 54 13s 5 300 0. 12 0. 57 132 182 0. 15 0. 53 132 138 D0 1,000 0.15 0. 52 138 144 0. 12 0. 50 132 133 Compound V 100 o. 11 0. 50 155 0. 14 0. 50 110 1 300 o. 15 0. 72 132 21s 0. 17 0. 55 144 173 1)0 1, 000 0. 17 0. 57 125 15s 0. 19 0. 52 120 125 TABLE Fresh materials Stored materials Speed S eed Mg. per kg. p Compound added emulsion Fog Grad. I II Fog Grad. I II 0. 03 0. 53 100 100 0. 05 0. 4s 86 Polyethylene glycol having an average molecular Weight of p,000 100 0. 0s 0. 64 174 340 0. 2e 0. 55 132 152 Compound 111 1,000 0.09 0. 04 166 346 0. 07 0.65 182 200 Compound IX- 1, 000 0.07 0. 57 152 228 0.08 0. 50 182 110 EXAMPLE 4 TABLE Fog (hydroquinone/ To a series of 1dent1calchem1cally ripened silver chloro- 2O p-monornethylarninobromide emulsions (25 mole percent of bromide) suitable f fi pheml devempmem) for the reproduction of line and screen-images, which 0 d d develop- Fresh Stored contain 5 -methyl-7-hydroXy-s-triazolo[l,5-a]pyrimidine, de mammals mammals cadmium chloride and a spectral sensitizer, one of the Polyethyleiielgllycol hafiring an avcompounds listed in the table below were added in an 25 3353 5 3 gg gg ggggg 10 amount of 100 mg. per mole of silver halide. g g g 153 23 After the addition of coating aid, 25% by weight of a Agata 953 H M7 0'23 latex-plasticizer calculated on the weight of gelatin and 8 31 31213 1 2 0.06 0.22 formaldehyde as hardening agent, the emulsion samples 8 3 13 fii:::: 3 8g 8 were all coated in a similar way on a cellulose tnacetate Hm its h f uh support and dried. 0 e

In a first experiment, the materials were exposed through a SOHUHUOBS wedge in order to examine the for- I" N CHZCHIO CHQ CHOH CH: mation of peppers due to infectlous development.

The examination of the peppers occurs visually after E development for 2.5 minutes at 20 C. in a developing CH CH5 bath, havmg the following composition. I

G. Sodium bisulphite 1.5 40 Hydroquinone 17 Formaldehyde bisulphite 60 Anhydrous sodium carbonate 60 g ifi iggi gg blcarbonate r the above results appears that contrary to the pounds of the present invention polyethylene glycols Water to make 1000 ml.

A value of 0 to 5 is given to the number of peppers observed, which values should be interpreted as follows:

The results attained are listed in the table hereinafter.

In a second experiment, the materials were developed for 4 minutes at 20 0., without being previously exposed, in a normal hydroquinone/p-monomethyl aminophenol developer having the following composition:

Water (40 C.) ml 800 p-Monomethylaminophenol sulphate -g 1.5 Anhydrous sodium sulphite g Hydroquinone g 6 Anhydrous sodium carbonate g 32 Potassium bromide g 2 Water to make 1000 ml.

The fog produced in materials developed immediately after preparation and materials that were developed after having been stored for 36 hours at 57 C. and 34% of relative humidity is listed in the table hereinafter.

when used in materials for the reproduction of line and screen-images give rise to the formation of a large number of peppers after infectious development. The same applies to compounds formed by polyaddition of a bisepoxide as used for the formation of the compounds of the invention with a N-alkyl-hydroxyalkylamine (compounds as described and claimed in United Kingdom patent specification 1,184,434 mentioned above).

The results also show that after development in a conventional p-monomethylaminophenol/hydroquinone developer the compounds of the present invention just like those of the above United Kingdom patent specification give less fog than polyethylene glycols.

When repeating the first experiment with the difference that the compounds of the invention were now incorporated in an amount of 0.05 g. per litre in the infectious-developer, the same favourable results as regards formation of peppers were attained.

We claim:

1. A process for developing an exposed photographic material containing light-sensitive silver halide, wherein the development is carried out with a water-soluble polymeric compound obtained by polyaddition of a dihydric alcohol corresponding to the formula:

HO--XOH wherein: X stands for arylene, a straight-chain or branched-chain alkylene, alkenylene or alkynylene group which has from 2 to 8 C-atoms, cycloalkylene or alkylene-cycloalkylene, with a bisepoxide corresponding to the formula:

wherein: Z stands for a straight-chain or branched-chain alkylene group which has from 2 to 8 C-atoms, being present in the development medium.

2. A process accordinng to claim 1, wherein the said water-soluble polymeric compound comprises recurring units of the following structure:

wherein:

X stands for arylene, a straight-chain or branched-chain alkylene, alkenylene or alkynylene group which has from 2 to 8 C-atoms, cycloalkylene or alkylene-cycloalkylene,

Z stands for a straight-chain or branched-chain alkylene group which has from 2 to 8 C-atoms,

R stands for hydrogen, an alkyl group, a -COR group, a CONHR group or a -SO R group, R standing for a monovalent saturated or unsaturated aliphatic group, a --COCH=CHCOOH group or its bisulphite addition product, a -COC H $O H group, an aryl group or a heterocyclic group.

3. A process according to claim 1, wherein Z stands for ethylene or tetramethylene.

4. A process accordinng to claim 1, wherein a silver chloride or silver chlorobromide emulsion, which comprises at most 50 mole percent of silver bromide suitable for the production of line and screen prints is developed with a hydroquinone-formaldehyde bisulphite developer.

5. A photographic light-sensitive material which comprises a silver halide emulsion layer or a water-permeable layer adjacent to a silver halide emulsion layer containing a water-soluble polymeric compound obtained by polyaddition of a dihydric alcohol correspondinng to the formula:

HO-X-OH wherein:

X stands for arylene, a straight-chain or branched-chain alkylene, alkenylene or alkynylene group which has from 2 to 8 C-atoms, cycloalkylene or alkylene-cycloalkylene,

with a bisepoxide corresponding to the formula:

wherein: Z stands for a straight-chain or branched-chain alkylene group which has from 2 to 8 C-atoms. 6. A photographic material according to claim 5, wherein the said water-soluble polymeric compound comprises recurring units of the following structure:

wherein:

X stands for arylene, a straight-chain or branched-chain alkylene, alkenylene or alkynylene group which has from 2 to *8 C-atoms, cycloalkylene or alkylene-cycloalkylene,

Z stands for a straight-chain or branched-chain alkylene group which has from 2 to 8 C-atoms,

R stands for hydrogen, an alkyl group, a COR group, a CONHR group or a --SO R group, R standing for a monovalent saturated or unsaturated aliphatic group, a --COCH=CHCOOH group or its bisulphite addition product, a --COC H.,-SO H group, an aryl group or a heterocyclic group.

7. A photographic material according to claim 5, wherein Z stands for ethylene or tetramethylene.

8. A photographic material according to claim 5, wherein the said polymeric compound is present in an amount comprised between 10 mg. and 5 g. per mole of silver halide.

9. A photographic material according to claim 5, wherein the said silver halide emulsion is a silver chloride emulsion or a silver chlorobromide emulsion, which comprises at most 50 mole percent of bromide, suitable for the production of line and screen prints.

10. A photographic developing composition comprising a silver halide developing agent and a water-soluble polymeric compound obtained by polyaddition of a dihydric alcohol corresponding to the formula:

wherein:

X stands for arylene, a straight-chain or branched-chain alkylene, alkenylene or alkynylenegroup which has from 2 to 8 C-atoms, cycloalkylene or alkylene-cycloalkylene,

with a bisepoxide corresponding to the formula:

wherein: Z stands for a straight-chain or branched-chain alkylene group which has for 2 to 8 C-atoms. 11. A photographic developing composition according to claim 10, wherein the said polymeric compound comprises recurring units of the following structure:

wherein:

X stands for arylene, a straight-chain or branched-chain alkylene, alkenylene or alkynylene group which has from 2 to 8 C-atorns, cycloalkylene or alkylene-cycloalkylene,

Z stands for a straight-chain or branched-chain alkylene group which has from 2 to 8 C-atoms,

R stands for hydrogen, an alkyl group, a COR group, a CONHR group or a --S0 R group, R standing for a monovalent saturated or unsaturated aliphatic group, a --COCH=CHCOOH group or its bisulphite addition product, a COC H.,-SO H group, an aryl group or a heterocyclic group.

12. A photographic developing composition according to claim 10, wherein Z is ethylene or tetramethylene.

13. A photographic developing composition according to claim 10, comprising hydroquinone and formaldehyde bisulphite.

14. A photographic developing composition according to claim 10, wherein the said polymeric compound is present in an amount comprised between 10 mg. and 5 g. per litre.

15. The process according to claim 1 wherein said water-soluble polymeric compound is present in the photographic material.

16. The process according to claim 1 wherein said water-soluble polymeric compound is in a developing bath.

17. The process according to claim 1 wherein the hydrogen atoms of the hydroxyl groups of said polyaddition compound are unsubstituted.

18. The process according to claim 1 wherein the hydrogen atoms of the hydroxyl groups of said polyaddition compound are at least partially substituted.

19. The photographic light-sensitive material of claim 5 wherein the hydrogen atoms of the hydroxyl groups of said polyaddition compound are unsubstituted.

20. The photographic light-sensitive material of claim 5 3,158,484 11/ 1964 Willems et al. 96114 wherein the hydrogen atoms of the hydroxyl groups of 3,189,459 6/1965 Burness 96-114 said polyaddition compound are at least partially sub- 3,398,201 8/1968 Glickman 96-1 14 stituted. 3,551,152 12/1970 Mackey 96-114 21. The developing composition of claim 10 wherein 5 3,625,692 12/1971 Meyer 96--114.5 the hydrogen atoms of the hydroxyl groups and the poly- FOREIGN PATENTS addition compound are unsubstituted.

22. The developing composition of claim 10 wherein the hydrogen atoms of the hydroxyl groups and the polyaddition compound are at least partially substituted. 10 NORMAN TORCHIN, r y Examiner M. F. KELLEY, Assistant Examiner 949,644 2/1964 Great Britain 9666.3

References Cited UNITED STATES PATENTS Us. CL XR.

3,047,394 7/1962 Allen et a1. 96-114 96-66, 95, 114 3,091,537 5/1963 Burness 96114 15 

